Sick water?

EXECUTIVE SUMMARY

The world is facing a global water quality crisis. Continuing population growth and ur- banisation, rapid industralisation, and expanding and intensifying food production are all putting pressure on water resources and increasing the unregulated or illegal discharge of contaminated water within and beyond national borders. This presents a global threat to hu- man health and wellbeing, with both immediate and long term consequences for efforts to reduce poverty whilst sustaining the integrity of some of our most productive ecosystems. There are many causes driving this crisis, but it is clear that freshwater and coastal eco- systems across the globe, upon which humanity has depended for millennia, are increas- ingly threatened. It is equally clear that future demands for water cannot be met unless wastewater management is revolutionized.

Global populations are expected to exceed nine billion by 2050. Urban populations may rise nearly twice as fast, projected to nearly double from current 3.4 billion to 6.4 billion by 2050, with numbers of people living in slums rising even faster, from one to 1.4 billion in just a decade. Over a fifth of the global to- tal, 1.6 billion people are expected to live by the coast by 2015. Inadequate infrastructure and management systems for the in- creasing volume of wastewater that we produce are at the heart of the wastewater crisis. The way we produce our food uses 70–90 per cent of the avail- able fresh water, returning much of this water to the system with additional nutrients and contaminants. It is a domino ef- fect as downstream agricultural pollution is joined by human and industrial waste. This wastewater contaminates freshwa- ter and coastal ecosystems, threatening food security, access to safe drinking and bathing water and providing a major health and environmental management challenge. Up to 90 per cent of wastewater flows untreated into the densely populated coast- al zone contributing to growing marine dead zones, which al- ready cover an area of 245 000 km 2 , approximately the same area as all the world’s coral reefs.

Contaminated water from inadequate wastewater management provides one the greatest health challenges restricting develop- ment and increasing poverty through costs to health care and lost labour productivity. Worldwide, almost 900 million people still do not have access to safe water and some 2.6 billion, al-

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